In recent years, with the improvement in image quality from VGA (Video Graphics Array) to XGA (extended Graphics Array) in flat-panel displays represented by LCD television sets and plasma television sets, signal speed for transferring image information is increasing. Accordingly, as a system for use in high-speed digital data transmissions, a differential transmission system of low amplitude has been used. The transmission system is provided for transmitting signals having phases opposite to each other and amplitudes equal to each other via one balanced cable or two wiring patterns formed on or a printed wiring board. The system has the features of small noise, strong resistance to external noises, small voltage amplitude, high-speed data transmission and so on, and has been introduced as a high-speed transmitting method particularly in the field of displays. However, since the differential transmission system requires two wiring lines for the transmission of one data bit, there has been such a problem that, when a plurality of data bits are transmitted, the number of the wiring lines comparatively increases and the wiring region on the printed wiring board is widened.
According to the signal transmitting system of the prior art described in the Patent Document 1, it is possible to achieve differential transmission of each of two data bits by using three (four by the conventional differential transmission system) transmission conductors including one complementary data line. In addition, it is possible to achieve differential transmission of each of four data bits by using five (eight by the conventional differential transmission system) transmission conductors including one complementary data line. Therefore, it is possible to reduce the number of transmission conductors as compared with the above mentioned conventional differential transmission system.
Patent document 1: Japanese patent laid-open publication No. JP-11-231984-A
Patent document 2: Japanese patent laid-open publication No. JP-2004-289626-A
Patent document 3: Specification of United States Patent Application Publication No. 2003/0043926